There are two mechanisms by which deuterium changes the expression of genes.
When deuterium populates the deoxyribose sugar backbone moiety that forms the double helix in DNA, there are conformational changes that frame shift the expression of genetic material without small nuclear polymorphism (SNPs) or epigenetic events. Excess deuterium can cause major genomic transformation in living organisms. This deserves the question whether SNPs and mutations are merely symptoms of weakening cellular energetics which is now referred to as “Epigenetics”?
The addition of a deuterium atom into the newly formed DNA increases the size and hydrogen (1H; P+) bond strength in DNA by about 8 to15 times or, about one magnitude as deuterium’s nucleus (2H; P+N) is twice the size and weight of hydrogen. If this happens more frequently, the cell will end up with additional DNA in the cytoplasm or nucleus or both. A normal human cell wraps all newly synthesized DNA in 46 chromosomes before dividing. If there is too much DNA, the cell will produce additional chromosomes to wrap it all up neatly. This is called aneuploidy or cancer. For example, a pancreatic cancer cell (MIA PaCa) will have 52 chromosomes, a metastatic lung cancer cell 61 (H441).
This is why we call deuterium an oncoisotope.